The effects of preoperative immunosuppressive therapy on ischemia and reperfusion (I/R) injury in healthy rats

Evaluation of nefrotoxicity by tacrolimus and micophenolate mofetil associated with kidney ischemia and reperfusion: experimental study in rats

OBJECTIVE

to evaluate the renal toxicity caused by tacrolimus and mycophenolate mofetil (MMF) in a single kidney ischemia and reperfusion model.

METHOD

experimental study using Wistar rats, submitted to right nephrectomy and left renal ischemia for 20 minutes, separated into groups in the postoperative period (PO): 1) Control (nonoperated); 2) Sham (operated, without PO drug); 3) TAC0.1, TAC1 and TAC10, tacrolimus administered PO at doses of 0.1mg/kg, 1mg/kg and 10mg/kg via gavage, respectively; 4) MMF, administered mycophenolate mofetil 20mg/kg; 5) MMF/TAC1 and MMF/TAC0.5, with an association of mycophenolate mofetil 20mg/kg and tacrolimus 1mg/kg and 0.5mg/kg, respectively. They were killed on the 14th PO and the kidney was removed for tissue oxidative stress analysis, by the dosage of reduced glutathione (GSH), lipoperoxidation (LPO) and protein carbonylation (PCO), and histological analysis by glomerular stereology (Glomerular volume density, Numerical density glomerular and mean glomerular volume). Renal function was evaluated by the measurement of serum creatinine and urea.

RESULTS

both drugs caused alterations in renal function, and the toxicity of tacrolimus was dose-dependent. Subacute toxicity did not show significant glomerular histological changes, and there was renal and compensatory glomerular hypertrophy in all groups except TAC10.

CONCLUSION

Both drugs cause changes in renal function. Glomerular morphometry and stereology showed negative interference of immunosuppressants during compensatory glomerular hypertrophy.

Avaliação da nefrotoxicidade pelo tacrolimus e micofenolato mofetil associados à isquemia e reperfusão renal: estudo experimental em ratos

RESUMO Objetivo: avaliar a toxicidade renal causada pelo tacrolimus e micofenolato mofetil (MMF) em um modelo de isquemia e reperfusão de rim único. Método: estudo experimental utilizando ratos Wistar, submetidos á nefrectomia direita e isquemia renal esquerda por 20 minutos, separados em grupos no pós- operatório (PO): 1) Controle (não operados); 2) Sham (operados, sem droga PO); 3) TAC0.1, TAC1 e TAC10, administrado tacrolimus no PO nas doses 0,1mg/kg, 1mg/kg e 10mg/kg via gavagem, respectivamentae; 4) MMF, administrado micofenolato mofetil 20mg/kg; 5) MMF/TAC1 e MMF/TAC0.5, com associação de micofenolato mofetil 20mg/kg e tacrolimus 1mg/kg e 0,5mg/kg, respectivamente. Foram mortos no 14º PO e retirado rim para análise do estresse oxidativo tecidual, pela dosagem de glutationa reduzida (GSH), lipoperoxidação (LPO) e carbonilação de proteínas (PCO), e análise histológica por estereologia glomerular (Densidade de volume glomerular, Densidade numérica glomerular e Volume glomerular médio). Foi avaliada função renal pela dosagem de creatinina e uréia séricas. Resultados: ambas drogas provocaram alteração na função renal, sendo a toxicidade do tacrolimus dosedependente. A toxicidade subaguda não mostrou alterações histológicas glomerulares significativas, sendo que houve hipertrofia renal e glomerular compensatória em todos os grupos exceto em TAC10. Conclusão: Ambas drogas provocam alteração na função renal. A morfometria e a estereologia glomerular mostraram interferência negativa dos imunossupressores durante a hipertrofia glomerular compensatória..

FK506 reduces liver ischemia-reperfusion injury in a rat model of autologous orthotopic liver transplantation by decreasing HMGB1 release

AIM

To evaluate the effect of tacrolimus (FK506) pretreatment on liver ischemia-reperfusion injury in a rat model of autologous orthotopic liver transplantation (AOLT).

METHODS

Thirty-two adult SD rats were randomly divided into four groups: sham-operated group (S), AOLT group, low dose FK506-treated group (L), and high dose FK506-treated group (H). After 6 h of reperfusion, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were detected using commercial assay kits. The histopathological changes in the rat liver were assessed by H&E staining. The high mobility group box 1 (HMGB1) expression was tested by immunohistochemistry, RT-qPCR and Western blot assays.

RESULTS

Compared with the S group, serum ALT, AST, TNF-α and IL-6 levels were markedly increased in the AOLT group, but decreased in the FK506-treated groups (P < 0.05). The histopathological changes in the liver of rats in the AOLT group included hepatic sinusoidal congestion, neutrophil infiltration, and hepatocyte necrosis, which were alleviated in the L group and H group. Compared with the S, L and H groups, there was a marked increase in HMGBl translocation and release in the AOLT group, but FK506 pretreatment (L and H groups) reduced the HMGB1 expression in hepatocytes. Compared with the S group, the expression of HMGB1 mRNA and protein also demonstrated a marked increase in the AOLT group, but decreased in the FK506 pretreatment groups. However, there was no significant difference in the above indicators between the L and H groups.

CONCLUSION

FK506 pretreatment has a protective effect against liver ischemia-reperfusion injury by inhibiting HMGB1 translocation and release, suppressing the release of inflammatory factors, and reducing hepatocyte necrosis in the AOLT rat model.